1. Field of Invention
This invention is concerned with a computer system board, specifically a computer system board with dual complete EMI shield and heat conduction housing solutions for critical environment applications.
2. Description of Prior Art
It is known in the art of the regular Personal Computer (PC) and industrial PC system board design, expansion slots are one of the key mechanisms on the board. They provide the hardware expandability of the system board. On a regular PC system board, ISA, PCI or PCMCIA slot can always be found. PC-104's interfaces were introduced to be the main expansion standard for stackable industrial PC. Add-on expansion daughter cards are mounted in to the expansion connectors/slots on the computer main system board/mother board for expanding the system functions. There is no strict requirement on the size of a regular PC system board. In art of computer system design, in order to eliminate the interference and having sufficient heat dissipation, the computer systems are designed with certain spacing and size to meet the requirements. To solve EMI and/or heat issues, the system board is usually designed in big size with sufficient spacing for the add-on expansion daughter cards. However, in the application cases where the hardware system sizes are limited, and the installation environment is critical such as outdoor application, and especially when there are RF circuitries and components in the system, the interference among the system board and add-on expansion daughter boards increases. Obviously, sufficient EMI proof means and heat conduction means are needed to be implemented, to ensure system function properly.
In the prior art of work, there are a variety of solutions to shield the components on a PCB, or shield a group of small assembly and then install them in a bigger PCB. Those designs provide a EMI shielding on the component level. However, on the system design level, especially, when an embedded computer system with different type of add-on expansion daughter cards, a system level EMI shield and heat conduction implementation is needed to ensure the whole system performance as well as keep the flexibility of the adaptation of different types of add-on expansion daughter cards.
Obviously, better solution is needed.